Attempts have been made to provide powdered compositions suitable for mixing with water, water+milk powder or milk for the manufacture of non-gelled acidified, milk containing product drinks. For example, US2008/0152777A1 provided a powdered composition that, upon mixing with water or milk, formed a non-gelled, acidified, milk-product drink without curdling of the milk protein. The composition contained 70-85% sugar, 0.15-0.4% artificial sweeteners, 7.15% citric acid, 0.6-1.6% buffering or acid bite reducing agent, 3.5-8% guar gum, 2-15% calcium fortification agent, and optional milk powder, emulsifiers, flavorants, colorants, vitamins, minerals, prebiotics, probiotic or fiber. The powdered composition was prepared by dry-blending sugars, citric acid, acid bit reducing agent, guar gum in a first step to homogeneously distribute guar gum. The remaining ingredients were added for dry-blending in a second stage. The beverage mix was prepared by mixing powder into water or milk and gentle stirring for 45 seconds to form a beverage with a pH less than 4.6. It was reported that guar gum was effective to prevent protein curdling, although it was not reported why this effect was present. Addition of fruit juice solids was reported in examples but not part of the claims.
Another patent, U.S. Pat. No. 4,530,850 provided a powdered composition that, upon mixing with milk, formed a non-gelled, acidified, milk-product drink without curdling of the milk proteins. The powdered composition contained about 1 to about 9 percent of an edible acid, about 0.5 to about 1.9 percent of an instant cold-water soluble gelatin, about 1 to about 10 percent of an edible natural or modified polysaccharide gum, about 20 to about 90 percent sweetening agents, and an effective amount of flavoring and coloring agents. The beverage was prepared by vigorously mixing (e.g. in a blender at high speed for 10 seconds or in a shaker for an unlisted time) the powdered composition into milk. It was reported that the gelatin included in the powder became attached to the casein in the milk, thereby stabilized the milk protein at lower pH; the gum was reportedly used to improve the viscosity and texture of the final beverage product. Attempts to reproduce the work reported in US2008/0152777A1 and U.S. Pat. No. 4,530,850 by the present inventors were generally unsuccessful. It is well known and has been reported by various patents, for example U.S. Pat. No. 6,652,896, that Na-CMC is effective to prevent milk protein curdling in liquid ready-to-drink beverages, when having a certain processing sequence and allowing Na-CMC and milk protein to establish in liquid conditions. No reports or positive results have been reported up to now, using Na-CMC in powdered beverages. Accordingly, there remains a need to find a suitable gum system for powdered beverage mixes containing milk, to provide a milk-containing beverage drink without protein curdling, having a smooth texture upon reconstitution with simple devices, e.g. a spoon.